Synthesis of Chiral Scaffolds Based on Polyfunctional Cyclobutane beta-Amino Acids

Chiral scaffolds have been synthesized through selective transformations from conveniently protected cyclobutane beta-amino acids. The obtained derivatives present additional functional groups, such as hydroxyl, carboxyl, or carbon-carbon triple bond, linked to the amino acid core through a flexible C-1 or C-2 alkyl fragment. The resultant molecules are highly versatile to be used as chiral precursors for the production of polyfunctional chemical platforms. These can be suitable for the synthesis of complex molecules, through condensation reactions, such as peptide coupling, dehydration between a carboxylic acid and an alcohol, or click chemistry. To illustrate some of these possibilities, two hybrid tripeptides have been prepared as examples of their synthetic potential.